ChopchopReader — Xuan An

ChopchopReader replaces the browser's PDF viewer with one built for reading papers. Hover a citation to see the full reference and its abstract without losing your place.

While reading
- Hover citations for the reference, abstract and a link to the paper
- Hover "Figure 3", "Table 2" or "Lemma 5" to preview it in place
- Hover footnote markers and acronyms to see what they say
- Back button, browser Back and mouse Back return you to where you were after following a link
Finding your way
- Sidebar with the outline, every figure and table, and the references ranked by how often they're cited
- Reading-time estimate for the main text and the appendix
- Links to the paper's code repositories
- Checks for a newer arXiv version, the published version, and retractions or corrections (only when you ask)
Notes
- Highlight, underline, comment and draw
- Notes are remembered for each paper, even if you open it again from a different link, and stay in sync across open tabs
- Save an annotated copy of the PDF

Works offline. Lookups go straight from your browser to public services (arXiv, OpenAlex, Crossref, Semantic Scholar, Google Scholar) only when you hover or click. Nothing is sent to any server of ours.

Based on Hover PDF by Zhisheng Jin, under the Apache License 2.0.